1. Field of the Invention
The present invention relates to an image forming apparatus such as a full color copying machine, a printer and the like adopting an electrophotographic system.
2. Related Background Art
In recent years, in general, as a plural color or full color image forming apparatus using an electrophotographic system, as shown in FIGS. 7A and 7B, an in-line type of the image forming apparatus has been disclosed in Japanese Patent Application Laid-Open No. 2001-242680, Japanese Patent Application Laid-Open No. 2003-202728, and Japanese Patent Application Laid-Open No. 2004-85899, in which a photosensitive member drum 1000 is lined up in a plurality according to each color, and the toner image of each color formed on each photosensitive member drum 1000 is superposed in order on an intermediate transferring belt 1010 to form a color image, and after the secondary transfer of the toner image on a sheet (recording material) to be conveyed, the toner image is heat-fixed by fixing means 1050, and is discharged into a discharge tray 1020. These constitutions, in which an exposing apparatus is disposed at the underside, can shorten a moving distance from the intermediate transferring member until the toner image is transferred on the recording member, and are effective in reduction of a first copy time.
In such image forming apparatus, in the image forming apparatus having the above described constitution, to remove a sheet jammed (sheet cogging) in a sheet conveying path, a unit retaining the sheet conveying path is rotatably constituted as a front door unit 1040, and the sheet conveying path from a cassette to the fixing apparatus device is made releasable.
On the other hand, since the intermediate transferring belt 1010 has also frequent entangling of the recording material occurred to it, it is desirable to open the intermediate transferring belt 1010. Particularly, in Japanese Patent No. 02865893, it is disclosed, an apparatus having a door to release the conveying path and a door to exchange an image forming unit. It, however, is difficult to remove the recording material from the intermediate transferring member effectively since the intermediate transferring member is not sufficiently opened.
To cope with this situation, as shown in Japanese Patent Application Laid-Open No. 2004-85899 as shown in FIG. 7B, to easily process the entangling of the sheet to the intermediate transferring belt 1010, an upper door unit 1030 having a discharge tray 1020 and the intermediate transferring belt 1010 is rotatably constituted for the image forming apparatus. As a result, because of the opening of the front door unit 1040, it is easy to access the conveying path, and by pivoting the upper door unit 1030 toward above the main body (in the direction to an arrow C in FIG. 7), an access to the intermediate transferring belt 1010 is made easy. As a result, jam processing of the conveying path of the sheet can be improved.
However, in the constitution where an open-close member to open the conveying path and an open-close member to open the intermediate transferring member are provided respectively in this manner, if fixing means is attached to either of the open-close members, there arises a following problem. That is, if the fixing means is attached to the open-close member capable of opening and closing upward in the vertical direction, there arise a problem of a lack of stability at the releasing time due to the weight of the fixing means, and also a problem of the constitution becoming complicated due to the necessity of enhancing rigidity of an open-close cover so as to be similarly endurable with the weight of the fixing means when the fixing means is attached to the open-close cover of the side surface.